Research on Nitrate Intake and Pancreatic Cancer Risk
Study Overview
Researchers at the National Cancer Institute (USA) investigated the connection between nitrate intake levels and the risk of pancreatic cancer in postmenopausal women. The pancreas, a crucial gland located behind the lower stomach, plays a vital role in digestion by producing enzymes and hormones such as insulin and glucagon, which regulate blood sugar levels. Pancreatic cancer is a serious condition with a high mortality rate due to its often asymptomatic development, leading to late-stage diagnosis when treatment becomes challenging. It ranks as the twelfth most common cancer and is the fourth leading cause of cancer-related deaths in the United States.
Nitrate Sources and Cancer Risks
Smoking is a well-established risk factor for pancreatic cancer. Additionally, there is growing concern about substances like nitrate, nitrite, and disinfection by-products that may contaminate drinking water, potentially linking them to pancreatic cancer. Nitrates and nitrites are also prevalent in processed meats. To explore this potential link, researchers conducted a study involving a large cohort of postmenopausal women participating in the Iowa Women’s Health Study, with findings published in the International Journal of Cancer.
Details of the Iowa Women’s Health Study
The Iowa Women’s Health Study began in 1986 when researchers randomly selected over 40,000 women aged 55 to 69 from Iowa Driver’s License records. Participants completed a detailed questionnaire covering their demographic data, dietary habits, family cancer history, medical history, and reproductive information. Follow-up questionnaires were distributed in subsequent years, with the 1989 survey specifically inquiring about the participants’ primary drinking water source and duration of use. This data, combined with assessments of contaminants in public water supplies, allowed researchers to estimate nitrate exposure through drinking water.
Findings on Nitrate and Pancreatic Cancer
The study identified 313 cases of pancreatic cancer among more than 34,000 women, including 152 cases from nearly 16,000 women who had utilized public water supplies for over ten years. Statistical analysis revealed no significant association between average nitrate ingestion from public water supplies and pancreatic cancer risk. However, a positive correlation was noted between high nitrite intake from processed meats and pancreatic cancer.
Conclusion
Researchers concluded that the data did not support a link between nitrate levels in drinking water and pancreatic cancer. However, high nitrate intake from processed meats may pose a risk factor for pancreatic cancer, although this association was based on a limited number of cases.
Reference
Quist A, Inoue-Choi M, Weyer P, et al. Ingested nitrate and nitrite, disinfection by-products, and pancreatic cancer risk in postmenopausal women. Int J Cancer 142, 251-261 (2018) 2017 UICC.